Cryoblation catheter handle

ABSTRACT

A cryocatheter system includes a first handle portion having a proximal end, a distal end, a first fluid flow path, and a second fluid flow path; a second handle portion having a proximal end, a distal end, a first fluid flow path, and a second fluid flow path; and a catheter having a proximal end, a distal end, a first fluid flow path, and a second fluid flow path. The distal end of the first handle portion is matable with the proximal end of the second handle portion to place the respective first and second fluid flow paths of each handle portion in fluid communication; and the distal end of the second handle portion is matable with the proximal end of the catheter to place the respective first and second fluid flow paths of the second handle portion and the catheter in fluid communication.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority from U.S. Provisional PatentApplication Serial No. 60/130,538, filed Apr. 21, 1999.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

[0002] Not applicable.

FIELD OF THE INVENTION

[0003] This invention relates to catheters, and more particularly tohandles and connectors for cryogenic catheters.

BACKGROUND OF THE INVENTION

[0004] A cryocatheter can generally be described as an elongate,slender, flexible body that is capable of delivering extreme cold toprovide a medically therapeutic effect. Such a catheter can be a part ofa system that includes several components, such as a console, anumbilical, a cryoblation catheter and a handle.

[0005] The console houses the electronics and software for controllingan ablation procedure. Additionally, the console controls delivery of arefrigerant through the umbilical to the catheter and recovery of therefrigerant from the catheter.

[0006] The umbilical connecting the catheter and handle to the consoleprovides mechanical connections for refrigerant transport and electricalconnection for electrical devices and sensors. The handle, in additionto providing an appropriate graspable structure, can include controlsfor catheter steering, as well as other catheter functions.

[0007] Known cryocatheter systems provide a unitary handle and catheterwhich is intended for a single use. As with other devices, attention tothe percentage and content of a system that is disposable (or that whichmust be disposed of for sanitary reasons), as well as attention to thecost of replacement items, can have a substantial effect on the cost ofacquisition and operation of the system. Thus, if possible, it wouldhelp to reduce cost of the system if only the catheter (or a portionthereof) were disposable and, under most circumstances, the handle wereavailable for reuse.

[0008] Ideally, the inclusion of disposable system elements does notcompromise system performance or patient safety. However, known attemptsto provide disposable catheter elements have been less than ideal. Forexample, providing a catheter that is removable from the handle requiresnot only connection to refrigerant, steering elements and electricalelements, but also a creation of a fluid-tight seal at thecatheter/handle interface. Not only can it be tedious to make suchconnections, known devices with this type of feature have not proved tobe acceptable with respect to either performance or safety. It wouldtherefore be desirable to provide a cryocatheter and handle thatprovides the benefits of a disposable component and which is easy touse, without safety or performance limitations.

SUMMARY OF THE INVENTION

[0009] The present invention provides a cyrocatheter system having atwo-part handle that is easy to connect and use; but the system does notcompromise safety and performance requirements.

[0010] In an exemplary embodiment, a cryocatheter system includes afirst handle portion having a proximal end, a distal end, a first fluidflow path, and a second fluid flow path; a second handle portion havinga proximal end, a distal end, a first fluid flow path, and a secondfluid flow path; and a catheter having a proximal end, a distal end, afirst fluid flow path, and a second fluid flow path. The distal end ofthe first handle portion is matable with the proximal end of the secondhandle portion to place the respective first and second fluid flow pathsof each handle portion in fluid communication; and the distal end of thesecond handle portion is matable with the proximal end of the catheterto place the respective first and second fluid flow paths of the secondhandle portion and the catheter in fluid communication.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] A more complete understanding of the present invention, and theattendant advantages and features thereof, will be more readilyunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings, wherein:

[0012]FIG. 1 illustrates a cryocatheter system generally;

[0013]FIG. 2 illustrates an exemplary embodiment of a handle as shown inFIG. 1, wherein the two handle portions are not mated;

[0014]FIG. 2A depicts the first and second handle portions of FIG. 2 ina mated state;

[0015]FIG. 3 shows an alternative embodiment of a two-part handle;

[0016]FIG. 4 is an exploded view of a two-part co-axial handle;

[0017]FIG. 5 is a sectional view of the two-part co-axial handle of FIG.4 in a partially mated state;

[0018]FIG. 6 illustrates additional features of the handle of FIG. 4 inan exploded cut-away view;

[0019]FIG. 7 is a sectional view of another embodiment of a co-axialconnection; and

[0020]FIG. 8 is yet another embodiment of a co-axial connection.

DETAILED DESCRIPTION OF THE INVENTION

[0021]FIG. 1 depicts a cryocatheter system in accordance with theinvention. The system includes a catheter 10, such as those disclosed inU.S. Pat. Nos. 5,899,898 and 5,899,899 to Arless, which are incorporatedherein by reference. The system also includes a handle 12 having a firstportion 14 and a second portion 16. First and second umbilicals 18 and20, respectively, connect the second portion 16 of the handle 12 to aconsole 22. The first umbilical 18 provides a path for a liquid or gasrefrigerant to be transferred between the console 22 and the handle 12;and the second umbilical 20 provides a signal path, such as forelectrical signals, between the console 22 and the handle. Additionalumbilicals can be provided as required, and the functions of more thanone umbilical can be provided in a single, multifunction umbilical.Further, additional devices, such as a connector box 24 can be placed inelectrical communication with an umbilical. As shown in FIG. 1, theconnector box 24 provides for connection to ECG apparatus (not shown).Also, one or more of the umbilicals can be divisible into two or moreportions as shown in FIG. 1, wherein the first umbilical includesportion 18 and 18′, and the second umbilical includes portions 20 and20′.

[0022] Referring now to FIG. 2, additional details of an exemplarytwo-part handle 12 are discussed in greater detail. A first handleportion 14 is shown mated to a cryocatheter 10 and a second handleportion 16 is shown mated to a single, multipurpose umbilical 26. Thefirst handle portion 14 defines or includes a portion of a first fluidpathway 28 and a portion of a second fluid pathway 30. The second handleportion 16 defines or contains a second portion of the first fluidpathway 28′ and a second portion of the second fluid pathway 30′. Whenthe first and second portions of the first and second fluid pathways aremated, as shown in FIG. 2A, continuous fluid paths are provided.Similarly, the first handle portion 14 includes a portion of one or moreelectrical or fiber-optic lines 31 and the second handle portion 16includes a second portion of the one or more electrical or fiber-opticlines 31′. Further, the first handle portion 14 includes a portion ofone or more steering elements, such a pull wire 33 and the second handleportion 16 includes a second portion of the steering elements 33′.

[0023] The first and second handle portions, as well as the first andsecond fluid pathways, one or more electrical or fiber-optic lines, andone or more steering elements are held together by complimentary lockingelements 32 and 34 as is known in the art, such as locking clips,bayonet, or twist-lock. Similarly, the fluid paths are mated withcouplings, the wires with electrical connectors, and the steeringelements with mechanical connectors. Thus, in the exemplary embodiment,the catheter 10 can be disconnected from the umbilical 14 and discarded,while allowing the first handle portion 18, which can include steeringmechanisms and other controls, to be retained for further use.

[0024] Whereas FIG. 2 shows a steering actuator, such as a thumb wheel,for selectively positioning a steering element in the second portion 16of the handle 12, FIG. 3 shows an arrangement where the steeringactuator 36 is located in the first portion 14. Additional featuresvisible in FIG. 3 include a blood sensor 38 located and configured insuch a manner so as to detect blood being withdrawn from the catheter 10through a low pressure or vacuum exhaust line 40 along with refrigerantinjected through a supply tube 42. Also shown are electrical controls 44in communication with electrical wires 46.

[0025] In addition to the above features, the refrigerant injection andlow pressure or vacuum return lines can be configured coaxially eitherin an umbilical or in the handle as shown in FIG. 4. In thisillustration an umbilical 48, a first connector 50 or handle portion, asecond connector 52 or handle portion, and second umbilical 54 orcatheter are shown. The umbilical 48 includes an outer tube 56 and aninner tube 58. In the exemplary embodiment, the inner tube 58 provides apath for fluid (e.g., refrigerant) under positive pressure, whereas theouter tube 56 provides a path for fluid under reduced or low pressure(e.g., in connection to a vacuum pump 55). Thus, if a leak should occurat some point along the inner tube 58 or its connections to othercomponents, the low pressure environment allows the leak to becontained, thereby preventing refrigerant from escaping the umbilical48. Additional safety is provided by a sensor 59 in communication withthe low-pressure fluid path defined by the outer tube 56. The sensor 59is tuned to detect a change in pressure within the outer tube 56, andwhen a change is detected, fluid flow into the system is turned off, asa change in pressure can be an indicator that a leak is present in thesystem.

[0026] Continuing to refer to FIG. 4, the umbilical 48 is mated to thefirst connector 50 and the umbilical 54 is mated to the second connector52. The first connector 50 includes O-rings 60 and 62 and is matablewith the second connecter 52, as shown in greater detail in the figuresthat follow, to provide a fluid-tight connection. The first connector 50can be locked to the second connector 52 with the assistance of abayonet-type connection having complimentary protuberances 64 andengagement slots 66.

[0027]FIG. 5 is a cross-sectional view of the coaxial connector of FIG.4 along line 5-5. In this view, the first connector 50 is shown almostfully mated to the second connector 52. In this view the inner tube 58is shown mated to an inner portion 68 of the first connector 50. Theinner portion 68 defines a fluid path 69 leading to an outlet 70 that,when the first and second connectors 50 and 52 are mated, aligns with afluid inlet 72 to an injection tube 74. The O-ring 62 ensures goodsealing of the connection.

[0028] Similarly, the outer tube 56 is shown mated to an outer portion76 of the first connector 50. The outer portion defines a fluid path 78that is in fluid communication with a fluid path 80 defined by thesecond connector 52. The fluid path 80 leads to, and is in communicationwith a fluid path 82 in the umbilical 54. The O-ring 60 ensures a goodseal between the first and second connectors 50 and 52, respectively.

[0029]FIG. 6 is a cut-away view of the assembly shown in FIG. 6. In thisview, the fluid path 69, outlet 70, fluid inlet 72, fluid path 78, fluidpath 80 are all clearly visible.

[0030]FIG. 7 shows an alternative embodiment of a coaxial arrangement.Shown is a first connector 84 and a second connector 86. In thisembodiment, a male Leur taper fitting 88 is receivable within a femaleLeur taper receptacle 90 as complimentary locking threads 92 and 94 onthe first and second connectors are engaged. When the connectors arefully engaged an O-ring seal 96 prevents leakage for connecting fluidflow paths 98 and 100. Similarly, an o-ring seal 102 prevents leakagefor connecting fluid flow paths 104 and 106. Exemplary fluid flowthrough flow paths 104 and 106 is shown by arrows.

[0031] Yet another connector embodiment is shown in FIG. 8. Thisembodiment provides connections that are not coaxial. As shown, a firstconnector 108 is mated to an outer tube or catheter shaft 110 with arigid sleeve 112 and a flexible strain relief element. An fluidinjection tube 114 is connected to a high-pressure female connectorfitting 116 with a flexible connector tube 118. Electrical wires 120that pass through the outer tube 110 terminate at a female pin wireconnector 122. A pull-wire 124 passes through the outer tube 110 and apull-wire seal fitting 126 to a female pull-wire connector 128. Apull-wire tension adjuster 130 can also be provided.

[0032] A second connector 132 includes a male, high-pressure connector134 that is matable with the fitting 116 to provide a continuous fluidpath. A male pull-wire connector 136, matable with the connector 128, isaxially movable within a portion of the second connector 132 as shown bythe double-headed arrow. The connector 136 is secured to a pull-wire 137that is in turn secured to an actuator (such as element 36 shown inFIGS. 2 and 3). Thus, when the pull-wire 137 is moved axially, theconnector 136 moves axially. A bias force can be applied by a biaselement 138, such as a spring, to push the connector 136 to a selectedpoint when axial tension is reduced on the pull-wire. Also shown is amale wire pin connector 140.

[0033] A variety of modifications and variations of the presentinvention are possible in light of the above disclosure. It is thereforeunderstood that, within the scope of the appended claims, the presentinvention may be practiced otherwise than as specifically describedhereinabove.

What is claimed is:
 1. A cryocatheter system comprising: a first handleportion having a proximal end, a distal end, a first fluid flow path,and a second fluid flow path; a second handle portion having a proximalend, a distal end, a first fluid flow path, and a second fluid flowpath, wherein the distal end of the first handle portion is matable withthe proximal end of the second handle portion to place the respectivefirst and second fluid flow paths of each handle portion in fluidcommunication; and a catheter having a proximal end, a distal end, afirst fluid flow path, and a second fluid flow path, wherein the distalend of the second handle portion is matable with the proximal end of thecatheter to place the respective first and second fluid flow paths ofthe second handle portion and the catheter in fluid communication. 2.The cryocatheter of claim 1, further comprising a pressure sensor incommunication with one of the first and second fluid flow paths.
 3. Thecryocatheter of claim 1, further comprising a blood detector incommunication with one of the first and second fluid flow paths.
 4. Thecryocatheter of claim 1, wherein the first fluid flow path is coaxialwith second fluid flow path.
 5. The cryocatheter of claim 4, wherein thefirst fluid flow path is defined by a refrigerant supply tube and thesecond fluid flow path is defined by a fluid exhaust tube.
 6. Thecryocatheter of claim 5, wherein the refrigerant supply tube is disposedwithin the fluid exhaust tube.
 7. The cryocatheter of claim 5, whereinthe fluid exhaust tube is in fluid communication with a vacuum source.8. The cryocatheter of claim 1, further comprising: a first pull-wiredisposed within the catheter, wherein the pull-wire has a proximal endthat is slidably engaged with the second handle portion; and a secondpull-wire having a distal end that is slidably engaged with the firsthandle portion, wherein the proximal end of the first pull-wire isengagable with the distal end of the second pull-wire.
 9. Thecryocatheter of claim 8, further comprising a bias element the axiallybiases the second pull-wire.
 10. A cryocatheter system comprising: afirst handle portion having a proximal end, a distal end, a first fluidflow path, and a second fluid flow path; a second handle portion havinga proximal end, a distal end, a first fluid flow path, and a secondfluid flow path, wherein the distal end of the first handle portion ismatable with the proximal end of the second handle portion to place therespective first and second fluid flow paths of each handle portion influid communication; a catheter having a proximal end, a distal end, afirst fluid flow path, and a second fluid flow path, wherein the distalend of the second handle portion is matable with the proximal end of thecatheter to place the respective first and second fluid flow paths ofthe second handle portion and the catheter in fluid communication; apressure sensor in communication with one of the first and second fluidflow paths; and a blood detector in communication with one of the firstand second fluid flow paths, wherein the first fluid flow path isdefined by a refrigerant supply tube and the second fluid flow path isdefined by a fluid exhaust tube, wherein the refrigerant supply tube isdisposed within the fluid exhaust tube, and wherein the fluid exhausttube is in fluid communication with a vacuum source.
 11. Thecryocatheter of claim 10, further comprising: a first pull-wire disposedwithin the catheter, wherein the pull-wire has a proximal end that isslidably engaged with the second handle portion; and a second pull-wirehaving a distal end that is slidably engaged with the first handleportion, wherein the proximal end of the first pull-wire is engagablewith the distal end of the second pull-wire.
 12. The cryocatheter ofclaim 11, further comprising a bias element the axially biases thesecond pull-wire.